I need to understand why we store our filament in moisture-controlled environment.

When I mount the reel in the printing environment (humid Michigan) it will begin the print with relatively dry filament. If it's a print that takes more than an hour or two, it will absorb moisture, and optimum printer settings will change.

It seems that elevated, but consistent, moisture level throughout the print would produce better results.

If your filament absorbs too much water, the water will vaporize and cause bubbles in your print. Storing in a low humidity environment will reduce the amount of moisture absorbed. If your filament has absorbed as much water as it can (how you can tell, I don't know...) and you're getting acceptable prints than I would say it doesn't matter. But to be on the safe side, I would still recommend storing in a controlled environment.

This method assumes that your bed and z-height have been leveled once but might be in need of minor adjustment from print to print. It also assumes that you are using Simplify3D, though it is likely to be adaptable to other printer-control software.

It may be desirable to pre-heat the bed to your printing temperature before starting.

In Simplify3D open the Bed Leveling Wizard (under Tools on the main screen) and set the "Z height for leveling moves" to 0.0. (In versions earlier than 2.1, it will be necessary to also keep the Machine Control Panel open and accessible on the screen. Depending on your computer and operating system this may involve resizing and repositioning these windows. Put the Machine Control panel in jog mode.)

Click the "Manually enter leveling positions" radio button and put the following locations in the manual portion of the dialog:

100 175100 75150 12550 125

Once entered, they will not need to be entered again. The first three coordinates are the locations of the adjustment screws in the spider. (Note: It would be nice to verify this or find the exact values.)

I was just browsing the MakerGear components page; they mention the position of the adjustment screws:

When the glass bed is mounted, the three spider mount screws are at (102.1,77.5), (102.1,177.5) and (152.1,127.5) with the front left corner of the glass at (0,0).